1. Field of the Invention
The invention relates to a wheel assembly with an in-wheel motor, which includes both a wheel driving apparatus formed of a motor or a combination of a motor and a reduction mechanism, and an oil supply apparatus that is driven by rotational output of the motor.
2. Description of the Related Art
Japanese Patent Application Publication No. 2005-73364 (JP-A-2005-73364), for example, describes a related wheel assembly with an in-wheel motor, which includes a motor, a rotating shaft that rotates according to output torque of the motor, an oil pump provided at one end of the rotating shaft, and an oil passage that supplies oil from the oil pump to an outer periphery of a stator core of the motor. In this wheel assembly with an in-wheel motor, the oil is supplied from the outer periphery of the stator core of the motor to cool the stator core and stator coil, after which it is used to lubricate bearings that support the shafts of the motor and a reduction gear.
Vehicles run backward as well as forward so in the wheel assembly with an in-wheel motor which is provided with an oil supply apparatus that is driven by rotational output of the motor, oil is preferably able to be supplied for cooling and/or lubricating the wheel driving apparatus during both forward (i.e., normal) rotation and reverse rotation of the motor.
With regard to this, as described in JP-A-2005-73364, the oil supply apparatus, which is structured taking into account only forward running of the vehicle, i.e., only forward rotation of the motor, may not be able to suitably supply oil to cool and/or lubricate the wheel driving apparatus when the vehicle is running in reverse, i.e., when the motor is operating in reverse.